Revert "convert SLB miss handlers to C" and subsequent commits

This reverts commits:
  5e46e29e ("powerpc/64s/hash: convert SLB miss handlers to C")
  8fed04d0 ("powerpc/64s/hash: remove user SLB data from the paca")
  655deecf ("powerpc/64s/hash: SLB allocation status bitmaps")
  2e162674 ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup")
  89ca4e12 ("powerpc/64s/hash: Add a SLB preload cache")

This series had a few bugs, and the fixes are not all trivial. So
revert most of it for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/asm-prototypes.h

@@ -78,8 +78,6 @@ void kernel_bad_stack(struct pt_regs *regs);
 void system_reset_exception(struct pt_regs *regs);
 void machine_check_exception(struct pt_regs *regs);
 void emulation_assist_interrupt(struct pt_regs *regs);
-long do_slb_fault(struct pt_regs *regs, unsigned long ea);
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err);
 
 /* signals, syscalls and interrupts */
 long sys_swapcontext(struct ucontext __user *old_ctx,

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -487,8 +487,6 @@ int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 extern void pseries_add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 
-extern void hash__setup_new_exec(void);
-
 #ifdef CONFIG_PPC_PSERIES
 void hpte_init_pseries(void);
 #else
@@ -503,7 +501,6 @@ struct slb_entry {
 };
 
 extern void slb_initialize(void);
-extern void core_flush_all_slbs(struct mm_struct *mm);
 extern void slb_flush_and_rebolt(void);
 void slb_flush_all_realmode(void);
 void __slb_restore_bolted_realmode(void);

arch/powerpc/include/asm/exception-64s.h

@@ -60,6 +60,14 @@
  */
 #define MAX_MCE_DEPTH	4
 
+/*
+ * EX_LR is only used in EXSLB and where it does not overlap with EX_DAR
+ * EX_CCR similarly with DSISR, but being 4 byte registers there is a hole
+ * in the save area so it's not necessary to overlap them. Could be used
+ * for future savings though if another 4 byte register was to be saved.
+ */
+#define EX_LR		EX_DAR
+
 /*
  * EX_R3 is only used by the bad_stack handler. bad_stack reloads and
  * saves DAR from SPRN_DAR, and EX_DAR is not used. So EX_R3 can overlap

arch/powerpc/include/asm/paca.h

@@ -113,10 +113,7 @@ struct paca_struct {
  				 * on the linear mapping */
 	/* SLB related definitions */
 	u16 vmalloc_sllp;
-	u8 slb_cache_ptr;
-	u8 stab_rr;			/* stab/slb round-robin counter */
-	u32 slb_used_bitmap;		/* Bitmaps for first 32 SLB entries. */
-	u32 slb_kern_bitmap;
+	u16 slb_cache_ptr;
 	u32 slb_cache[SLB_CACHE_ENTRIES];
 #endif /* CONFIG_PPC_BOOK3S_64 */
 
@@ -146,11 +143,24 @@ struct paca_struct {
 	struct tlb_core_data tcd;
 #endif /* CONFIG_PPC_BOOK3E */
 
+#ifdef CONFIG_PPC_BOOK3S
+	mm_context_id_t mm_ctx_id;
+#ifdef CONFIG_PPC_MM_SLICES
+	unsigned char mm_ctx_low_slices_psize[BITS_PER_LONG / BITS_PER_BYTE];
+	unsigned char mm_ctx_high_slices_psize[SLICE_ARRAY_SIZE];
+	unsigned long mm_ctx_slb_addr_limit;
+#else
+	u16 mm_ctx_user_psize;
+	u16 mm_ctx_sllp;
+#endif
+#endif
+
 	/*
 	 * then miscellaneous read-write fields
 	 */
 	struct task_struct *__current;	/* Pointer to current */
 	u64 kstack;			/* Saved Kernel stack addr */
+	u64 stab_rr;			/* stab/slb round-robin counter */
 	u64 saved_r1;			/* r1 save for RTAS calls or PM or EE=0 */
 	u64 saved_msr;			/* MSR saved here by enter_rtas */
 	u16 trap_save;			/* Used when bad stack is encountered */
@@ -248,6 +258,7 @@ struct paca_struct {
 #endif /* CONFIG_PPC_BOOK3S_64 */
 } ____cacheline_aligned;
 
+extern void copy_mm_to_paca(struct mm_struct *mm);
 extern struct paca_struct **paca_ptrs;
 extern void initialise_paca(struct paca_struct *new_paca, int cpu);
 extern void setup_paca(struct paca_struct *new_paca);

arch/powerpc/include/asm/processor.h

@@ -273,7 +273,6 @@ struct thread_struct {
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 	struct arch_hw_breakpoint hw_brk; /* info on the hardware breakpoint */
 	unsigned long	trap_nr;	/* last trap # on this thread */
-	u8 load_slb;			/* Ages out SLB preload cache entries */
 	u8 load_fp;
 #ifdef CONFIG_ALTIVEC
 	u8 load_vec;

arch/powerpc/include/asm/slice.h

@@ -32,7 +32,6 @@ void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 			   unsigned long len, unsigned int psize);
 
 void slice_init_new_context_exec(struct mm_struct *mm);
-void slice_setup_new_exec(void);
 
 #endif /* __ASSEMBLY__ */
 

arch/powerpc/include/asm/thread_info.h

@@ -29,7 +29,6 @@
 #include <asm/page.h>
 #include <asm/accounting.h>
 
-#define SLB_PRELOAD_NR	16U
 /*
  * low level task data.
  */
@@ -45,10 +44,6 @@ struct thread_info {
 #if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
 	struct cpu_accounting_data accounting;
 #endif
-	u8 slb_preload_nr;
-	u8 slb_preload_tail;
-	u32 slb_preload_esid[SLB_PRELOAD_NR];
-
 	/* low level flags - has atomic operations done on it */
 	unsigned long	flags ____cacheline_aligned_in_smp;
 };
@@ -77,12 +72,6 @@ static inline struct thread_info *current_thread_info(void)
 }
 
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-
-#ifdef CONFIG_PPC_BOOK3S_64
-void arch_setup_new_exec(void);
-#define arch_setup_new_exec arch_setup_new_exec
-#endif
-
 #endif /* __ASSEMBLY__ */
 
 /*

arch/powerpc/kernel/asm-offsets.c

@@ -173,6 +173,7 @@ int main(void)
 	OFFSET(PACAKSAVE, paca_struct, kstack);
 	OFFSET(PACACURRENT, paca_struct, __current);
 	OFFSET(PACASAVEDMSR, paca_struct, saved_msr);
+	OFFSET(PACASTABRR, paca_struct, stab_rr);
 	OFFSET(PACAR1, paca_struct, saved_r1);
 	OFFSET(PACATOC, paca_struct, kernel_toc);
 	OFFSET(PACAKBASE, paca_struct, kernelbase);
@@ -180,6 +181,15 @@ int main(void)
 	OFFSET(PACAIRQSOFTMASK, paca_struct, irq_soft_mask);
 	OFFSET(PACAIRQHAPPENED, paca_struct, irq_happened);
 	OFFSET(PACA_FTRACE_ENABLED, paca_struct, ftrace_enabled);
+#ifdef CONFIG_PPC_BOOK3S
+	OFFSET(PACACONTEXTID, paca_struct, mm_ctx_id);
+#ifdef CONFIG_PPC_MM_SLICES
+	OFFSET(PACALOWSLICESPSIZE, paca_struct, mm_ctx_low_slices_psize);
+	OFFSET(PACAHIGHSLICEPSIZE, paca_struct, mm_ctx_high_slices_psize);
+	OFFSET(PACA_SLB_ADDR_LIMIT, paca_struct, mm_ctx_slb_addr_limit);
+	DEFINE(MMUPSIZEDEFSIZE, sizeof(struct mmu_psize_def));
+#endif /* CONFIG_PPC_MM_SLICES */
+#endif
 
 #ifdef CONFIG_PPC_BOOK3E
 	OFFSET(PACAPGD, paca_struct, pgd);
@@ -202,7 +212,6 @@ int main(void)
 #ifdef CONFIG_PPC_BOOK3S_64
 	OFFSET(PACASLBCACHE, paca_struct, slb_cache);
 	OFFSET(PACASLBCACHEPTR, paca_struct, slb_cache_ptr);
-	OFFSET(PACASTABRR, paca_struct, stab_rr);
 	OFFSET(PACAVMALLOCSLLP, paca_struct, vmalloc_sllp);
 #ifdef CONFIG_PPC_MM_SLICES
 	OFFSET(MMUPSIZESLLP, mmu_psize_def, sllp);

arch/powerpc/kernel/exceptions-64s.S

@@ -596,36 +596,28 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 
 
 EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)
-EXCEPTION_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, KVMTEST_PR, 0x380);
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x380)
+	mr	r12,r3	/* save r3 */
+	mfspr	r3,SPRN_DAR
+	mfspr	r11,SPRN_SRR1
+	crset	4*cr6+eq
+	BRANCH_TO_COMMON(r10, slb_miss_common)
 EXC_REAL_END(data_access_slb, 0x380, 0x80)
 
 EXC_VIRT_BEGIN(data_access_slb, 0x4380, 0x80)
-EXCEPTION_RELON_PROLOG(PACA_EXSLB, data_access_slb_common, EXC_STD, NOTEST, 0x380);
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380)
+	mr	r12,r3	/* save r3 */
+	mfspr	r3,SPRN_DAR
+	mfspr	r11,SPRN_SRR1
+	crset	4*cr6+eq
+	BRANCH_TO_COMMON(r10, slb_miss_common)
 EXC_VIRT_END(data_access_slb, 0x4380, 0x80)
-
 TRAMP_KVM_SKIP(PACA_EXSLB, 0x380)
 
-EXC_COMMON_BEGIN(data_access_slb_common)
-	mfspr	r10,SPRN_DAR
-	std	r10,PACA_EXSLB+EX_DAR(r13)
-	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB)
-	ld	r4,PACA_EXSLB+EX_DAR(r13)
-	std	r4,_DAR(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_slb_fault
-	cmpdi	r3,0
-	bne-	1f
-	b	fast_exception_return
-1:	/* Error case */
-	std	r3,RESULT(r1)
-	bl	save_nvgprs
-	RECONCILE_IRQ_STATE(r10, r11)
-	ld	r4,_DAR(r1)
-	ld	r5,RESULT(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_bad_slb_fault
-	b	ret_from_except
-
 
 EXC_REAL(instruction_access, 0x400, 0x80)
 EXC_VIRT(instruction_access, 0x4400, 0x80, 0x400)
@@ -648,34 +640,160 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
 
 
 EXC_REAL_BEGIN(instruction_access_slb, 0x480, 0x80)
-EXCEPTION_PROLOG(PACA_EXSLB, instruction_access_slb_common, EXC_STD, KVMTEST_PR, 0x480);
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
+	mr	r12,r3	/* save r3 */
+	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
+	mfspr	r11,SPRN_SRR1
+	crclr	4*cr6+eq
+	BRANCH_TO_COMMON(r10, slb_miss_common)
 EXC_REAL_END(instruction_access_slb, 0x480, 0x80)
 
 EXC_VIRT_BEGIN(instruction_access_slb, 0x4480, 0x80)
-EXCEPTION_RELON_PROLOG(PACA_EXSLB, instruction_access_slb_common, EXC_STD, NOTEST, 0x480);
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
+	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x480)
+	mr	r12,r3	/* save r3 */
+	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
+	mfspr	r11,SPRN_SRR1
+	crclr	4*cr6+eq
+	BRANCH_TO_COMMON(r10, slb_miss_common)
 EXC_VIRT_END(instruction_access_slb, 0x4480, 0x80)
-
 TRAMP_KVM(PACA_EXSLB, 0x480)
 
-EXC_COMMON_BEGIN(instruction_access_slb_common)
-	EXCEPTION_PROLOG_COMMON(0x480, PACA_EXSLB)
-	ld	r4,_NIP(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_slb_fault
-	cmpdi	r3,0
-	bne-	1f
-	b	fast_exception_return
-1:	/* Error case */
-	std	r3,RESULT(r1)
+
+/*
+ * This handler is used by the 0x380 and 0x480 SLB miss interrupts, as well as
+ * the virtual mode 0x4380 and 0x4480 interrupts if AIL is enabled.
+ */
+EXC_COMMON_BEGIN(slb_miss_common)
+	/*
+	 * r13 points to the PACA, r9 contains the saved CR,
+	 * r12 contains the saved r3,
+	 * r11 contain the saved SRR1, SRR0 is still ready for return
+	 * r3 has the faulting address
+	 * r9 - r13 are saved in paca->exslb.
+ 	 * cr6.eq is set for a D-SLB miss, clear for a I-SLB miss
+	 * We assume we aren't going to take any exceptions during this
+	 * procedure.
+	 */
+	mflr	r10
+	stw	r9,PACA_EXSLB+EX_CCR(r13)	/* save CR in exc. frame */
+	std	r10,PACA_EXSLB+EX_LR(r13)	/* save LR */
+
+	andi.	r9,r11,MSR_PR	// Check for exception from userspace
+	cmpdi	cr4,r9,MSR_PR	// And save the result in CR4 for later
+
+	/*
+	 * Test MSR_RI before calling slb_allocate_realmode, because the
+	 * MSR in r11 gets clobbered. However we still want to allocate
+	 * SLB in case MSR_RI=0, to minimise the risk of getting stuck in
+	 * recursive SLB faults. So use cr5 for this, which is preserved.
+	 */
+	andi.	r11,r11,MSR_RI	/* check for unrecoverable exception */
+	cmpdi	cr5,r11,MSR_RI
+
+	crset	4*cr0+eq
+#ifdef CONFIG_PPC_BOOK3S_64
+BEGIN_MMU_FTR_SECTION
+	bl	slb_allocate
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
+#endif
+
+	ld	r10,PACA_EXSLB+EX_LR(r13)
+	lwz	r9,PACA_EXSLB+EX_CCR(r13)	/* get saved CR */
+	mtlr	r10
+
+	/*
+	 * Large address, check whether we have to allocate new contexts.
+	 */
+	beq-	8f
+
+	bne-	cr5,2f		/* if unrecoverable exception, oops */
+
+	/* All done -- return from exception. */
+
+	bne	cr4,1f		/* returning to kernel */
+
+	mtcrf	0x80,r9
+	mtcrf	0x08,r9		/* MSR[PR] indication is in cr4 */
+	mtcrf	0x04,r9		/* MSR[RI] indication is in cr5 */
+	mtcrf	0x02,r9		/* I/D indication is in cr6 */
+	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
+
+	RESTORE_CTR(r9, PACA_EXSLB)
+	RESTORE_PPR_PACA(PACA_EXSLB, r9)
+	mr	r3,r12
+	ld	r9,PACA_EXSLB+EX_R9(r13)
+	ld	r10,PACA_EXSLB+EX_R10(r13)
+	ld	r11,PACA_EXSLB+EX_R11(r13)
+	ld	r12,PACA_EXSLB+EX_R12(r13)
+	ld	r13,PACA_EXSLB+EX_R13(r13)
+	RFI_TO_USER
+	b	.	/* prevent speculative execution */
+1:
+	mtcrf	0x80,r9
+	mtcrf	0x08,r9		/* MSR[PR] indication is in cr4 */
+	mtcrf	0x04,r9		/* MSR[RI] indication is in cr5 */
+	mtcrf	0x02,r9		/* I/D indication is in cr6 */
+	mtcrf	0x01,r9		/* slb_allocate uses cr0 and cr7 */
+
+	RESTORE_CTR(r9, PACA_EXSLB)
+	RESTORE_PPR_PACA(PACA_EXSLB, r9)
+	mr	r3,r12
+	ld	r9,PACA_EXSLB+EX_R9(r13)
+	ld	r10,PACA_EXSLB+EX_R10(r13)
+	ld	r11,PACA_EXSLB+EX_R11(r13)
+	ld	r12,PACA_EXSLB+EX_R12(r13)
+	ld	r13,PACA_EXSLB+EX_R13(r13)
+	RFI_TO_KERNEL
+	b	.	/* prevent speculative execution */
+
+
+2:	std     r3,PACA_EXSLB+EX_DAR(r13)
+	mr	r3,r12
+	mfspr	r11,SPRN_SRR0
+	mfspr	r12,SPRN_SRR1
+	LOAD_HANDLER(r10,unrecov_slb)
+	mtspr	SPRN_SRR0,r10
+	ld	r10,PACAKMSR(r13)
+	mtspr	SPRN_SRR1,r10
+	RFI_TO_KERNEL
+	b	.
+
+8:	std     r3,PACA_EXSLB+EX_DAR(r13)
+	mr	r3,r12
+	mfspr	r11,SPRN_SRR0
+	mfspr	r12,SPRN_SRR1
+	LOAD_HANDLER(r10, large_addr_slb)
+	mtspr	SPRN_SRR0,r10
+	ld	r10,PACAKMSR(r13)
+	mtspr	SPRN_SRR1,r10
+	RFI_TO_KERNEL
+	b	.
+
+EXC_COMMON_BEGIN(unrecov_slb)
+	EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
+	RECONCILE_IRQ_STATE(r10, r11)
 	bl	save_nvgprs
+1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	unrecoverable_exception
+	b	1b
+
+EXC_COMMON_BEGIN(large_addr_slb)
+	EXCEPTION_PROLOG_COMMON(0x380, PACA_EXSLB)
 	RECONCILE_IRQ_STATE(r10, r11)
-	ld	r4,_NIP(r1)
-	ld	r5,RESULT(r1)
-	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	do_bad_slb_fault
+	ld	r3, PACA_EXSLB+EX_DAR(r13)
+	std	r3, _DAR(r1)
+	beq	cr6, 2f
+	li	r10, 0x481		/* fix trap number for I-SLB miss */
+	std	r10, _TRAP(r1)
+2:	bl	save_nvgprs
+	addi	r3, r1, STACK_FRAME_OVERHEAD
+	bl	slb_miss_large_addr
 	b	ret_from_except
 
-
 EXC_REAL_BEGIN(hardware_interrupt, 0x500, 0x100)
 	.globl hardware_interrupt_hv;
 hardware_interrupt_hv:

arch/powerpc/kernel/paca.c

@@ -258,3 +258,25 @@ void __init free_unused_pacas(void)
 	printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 			paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 }
+
+void copy_mm_to_paca(struct mm_struct *mm)
+{
+#ifdef CONFIG_PPC_BOOK3S
+	mm_context_t *context = &mm->context;
+
+	get_paca()->mm_ctx_id = context->id;
+#ifdef CONFIG_PPC_MM_SLICES
+	VM_BUG_ON(!mm->context.slb_addr_limit);
+	get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
+	memcpy(&get_paca()->mm_ctx_low_slices_psize,
+	       &context->low_slices_psize, sizeof(context->low_slices_psize));
+	memcpy(&get_paca()->mm_ctx_high_slices_psize,
+	       &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
+#else /* CONFIG_PPC_MM_SLICES */
+	get_paca()->mm_ctx_user_psize = context->user_psize;
+	get_paca()->mm_ctx_sllp = context->sllp;
+#endif
+#else /* !CONFIG_PPC_BOOK3S */
+	return;
+#endif
+}

arch/powerpc/kernel/process.c

@@ -1482,15 +1482,6 @@ void flush_thread(void)
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 }
 
-#ifdef CONFIG_PPC_BOOK3S_64
-void arch_setup_new_exec(void)
-{
-	if (radix_enabled())
-		return;
-	hash__setup_new_exec();
-}
-#endif
-
 int set_thread_uses_vas(void)
 {
 #ifdef CONFIG_PPC_BOOK3S_64
@@ -1719,8 +1710,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	return 0;
 }
 
-void preload_new_slb_context(unsigned long start, unsigned long sp);
-
 /*
  * Set up a thread for executing a new program
  */
@@ -1728,10 +1717,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 {
 #ifdef CONFIG_PPC64
 	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
-
-#ifdef CONFIG_PPC_BOOK3S_64
-	preload_new_slb_context(start, sp);
-#endif
 #endif
 
 	/*
@@ -1822,7 +1807,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 #ifdef CONFIG_VSX
 	current->thread.used_vsr = 0;
 #endif
-	current->thread.load_slb = 0;
 	current->thread.load_fp = 0;
 	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
 	current->thread.fp_save_area = NULL;

arch/powerpc/mm/Makefile

@@ -15,7 +15,7 @@ obj-$(CONFIG_PPC_MMU_NOHASH)	+= mmu_context_nohash.o tlb_nohash.o \
 obj-$(CONFIG_PPC_BOOK3E)	+= tlb_low_$(BITS)e.o
 hash64-$(CONFIG_PPC_NATIVE)	:= hash_native_64.o
 obj-$(CONFIG_PPC_BOOK3E_64)   += pgtable-book3e.o
-obj-$(CONFIG_PPC_BOOK3S_64)	+= pgtable-hash64.o hash_utils_64.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o
+obj-$(CONFIG_PPC_BOOK3S_64)	+= pgtable-hash64.o hash_utils_64.o slb_low.o slb.o $(hash64-y) mmu_context_book3s64.o pgtable-book3s64.o
 obj-$(CONFIG_PPC_RADIX_MMU)	+= pgtable-radix.o tlb-radix.o
 obj-$(CONFIG_PPC_STD_MMU_32)	+= ppc_mmu_32.o hash_low_32.o mmu_context_hash32.o
 obj-$(CONFIG_PPC_STD_MMU)	+= tlb_hash$(BITS).o

arch/powerpc/mm/hash_utils_64.c

@@ -1088,16 +1088,16 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
 }
 
 #ifdef CONFIG_PPC_MM_SLICES
-static unsigned int get_psize(struct mm_struct *mm, unsigned long addr)
+static unsigned int get_paca_psize(unsigned long addr)
 {
 	unsigned char *psizes;
 	unsigned long index, mask_index;
 
 	if (addr < SLICE_LOW_TOP) {
-		psizes = mm->context.low_slices_psize;
+		psizes = get_paca()->mm_ctx_low_slices_psize;
 		index = GET_LOW_SLICE_INDEX(addr);
 	} else {
-		psizes = mm->context.high_slices_psize;
+		psizes = get_paca()->mm_ctx_high_slices_psize;
 		index = GET_HIGH_SLICE_INDEX(addr);
 	}
 	mask_index = index & 0x1;
@@ -1105,9 +1105,9 @@ static unsigned int get_psize(struct mm_struct *mm, unsigned long addr)
 }
 
 #else
-unsigned int get_psize(struct mm_struct *mm, unsigned long addr)
+unsigned int get_paca_psize(unsigned long addr)
 {
-	return mm->context.user_psize;
+	return get_paca()->mm_ctx_user_psize;
 }
 #endif
 
@@ -1118,11 +1118,15 @@ unsigned int get_psize(struct mm_struct *mm, unsigned long addr)
 #ifdef CONFIG_PPC_64K_PAGES
 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
 {
-	if (get_psize(mm, addr) == MMU_PAGE_4K)
+	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
 		return;
 	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
 	copro_flush_all_slbs(mm);
-	core_flush_all_slbs(mm);
+	if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
+
+		copy_mm_to_paca(mm);
+		slb_flush_and_rebolt();
+	}
 }
 #endif /* CONFIG_PPC_64K_PAGES */
 
@@ -1187,6 +1191,22 @@ void hash_failure_debug(unsigned long ea, unsigned long access,
 		trap, vsid, ssize, psize, lpsize, pte);
 }
 
+static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
+			     int psize, bool user_region)
+{
+	if (user_region) {
+		if (psize != get_paca_psize(ea)) {
+			copy_mm_to_paca(mm);
+			slb_flush_and_rebolt();
+		}
+	} else if (get_paca()->vmalloc_sllp !=
+		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
+		get_paca()->vmalloc_sllp =
+			mmu_psize_defs[mmu_vmalloc_psize].sllp;
+		slb_vmalloc_update();
+	}
+}
+
 /* Result code is:
  *  0 - handled
  *  1 - normal page fault
@@ -1219,7 +1239,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 			rc = 1;
 			goto bail;
 		}
-		psize = get_psize(mm, ea);
+		psize = get_slice_psize(mm, ea);
 		ssize = user_segment_size(ea);
 		vsid = get_user_vsid(&mm->context, ea, ssize);
 		break;
@@ -1307,6 +1327,9 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 			WARN_ON(1);
 		}
 #endif
+		if (current->mm == mm)
+			check_paca_psize(ea, mm, psize, user_region);
+
 		goto bail;
 	}
 
@@ -1341,14 +1364,15 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 			       "to 4kB pages because of "
 			       "non-cacheable mapping\n");
 			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
-			slb_vmalloc_update();
 			copro_flush_all_slbs(mm);
-			core_flush_all_slbs(mm);
 		}
 	}
 
 #endif /* CONFIG_PPC_64K_PAGES */
 
+	if (current->mm == mm)
+		check_paca_psize(ea, mm, psize, user_region);
+
 #ifdef CONFIG_PPC_64K_PAGES
 	if (psize == MMU_PAGE_64K)
 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
@@ -1436,7 +1460,7 @@ int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
 #ifdef CONFIG_PPC_MM_SLICES
 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
 {
-	int psize = get_psize(mm, ea);
+	int psize = get_slice_psize(mm, ea);
 
 	/* We only prefault standard pages for now */
 	if (unlikely(psize != mm->context.user_psize))

arch/powerpc/mm/mmu_context.c

@@ -54,7 +54,8 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 		 * MMU context id, which is then moved to SPRN_PID.
 		 *
 		 * For the hash MMU it is either the first load from slb_cache
-		 * in switch_slb(), and/or load of MMU context id.
+		 * in switch_slb(), and/or the store of paca->mm_ctx_id in
+		 * copy_mm_to_paca().
 		 *
 		 * On the other side, the barrier is in mm/tlb-radix.c for
 		 * radix which orders earlier stores to clear the PTEs vs

arch/powerpc/mm/mmu_context_book3s64.c

@@ -53,8 +53,6 @@ int hash__alloc_context_id(void)
 }
 EXPORT_SYMBOL_GPL(hash__alloc_context_id);
 
-void slb_setup_new_exec(void);
-
 static int hash__init_new_context(struct mm_struct *mm)
 {
 	int index;
@@ -86,13 +84,6 @@ static int hash__init_new_context(struct mm_struct *mm)
 	return index;
 }
 
-void hash__setup_new_exec(void)
-{
-	slice_setup_new_exec();
-
-	slb_setup_new_exec();
-}
-
 static int radix__init_new_context(struct mm_struct *mm)
 {
 	unsigned long rts_field;

arch/powerpc/mm/slb.c

@@ -14,7 +14,6 @@
  *      2 of the License, or (at your option) any later version.
  */
 
-#include <asm/asm-prototypes.h>
 #include <asm/pgtable.h>
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
@@ -34,7 +33,7 @@ enum slb_index {
 	KSTACK_INDEX	= 1, /* Kernel stack map */
 };
 
-static long slb_allocate_user(struct mm_struct *mm, unsigned long ea);
+extern void slb_allocate(unsigned long ea);
 
 #define slb_esid_mask(ssize)	\
 	(((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
@@ -45,17 +44,11 @@ static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
 	return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | index;
 }
 
-static inline unsigned long __mk_vsid_data(unsigned long vsid, int ssize,
-					 unsigned long flags)
-{
-	return (vsid << slb_vsid_shift(ssize)) | flags |
-		((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
-}
-
 static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
 					 unsigned long flags)
 {
-	return __mk_vsid_data(get_kernel_vsid(ea, ssize), ssize, flags);
+	return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
+		((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
 }
 
 static inline void slb_shadow_update(unsigned long ea, int ssize,
@@ -122,9 +115,6 @@ void slb_restore_bolted_realmode(void)
 {
 	__slb_restore_bolted_realmode();
 	get_paca()->slb_cache_ptr = 0;
-
-	get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
-	get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
 }
 
 /*
@@ -132,6 +122,9 @@ void slb_restore_bolted_realmode(void)
  */
 void slb_flush_all_realmode(void)
 {
+	/*
+	 * This flushes all SLB entries including 0, so it must be realmode.
+	 */
 	asm volatile("slbmte %0,%0; slbia" : : "r" (0));
 }
 
@@ -177,9 +170,6 @@ void slb_flush_and_rebolt(void)
 		     : "memory");
 
 	get_paca()->slb_cache_ptr = 0;
-
-	get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
-	get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
 }
 
 void slb_save_contents(struct slb_entry *slb_ptr)
@@ -212,7 +202,7 @@ void slb_dump_contents(struct slb_entry *slb_ptr)
 		return;
 
 	pr_err("SLB contents of cpu 0x%x\n", smp_processor_id());
-	pr_err("Last SLB entry inserted at slot %u\n", get_paca()->stab_rr);
+	pr_err("Last SLB entry inserted at slot %lld\n", get_paca()->stab_rr);
 
 	for (i = 0; i < mmu_slb_size; i++) {
 		e = slb_ptr->esid;
@@ -257,119 +247,41 @@ void slb_vmalloc_update(void)
 	slb_flush_and_rebolt();
 }
 
-static bool preload_hit(struct thread_info *ti, unsigned long esid)
-{
-	u8 i;
-
-	for (i = 0; i < ti->slb_preload_nr; i++) {
-		u8 idx;
-
-		idx = (ti->slb_preload_tail + i) % SLB_PRELOAD_NR;
-		if (esid == ti->slb_preload_esid[idx])
-			return true;
-	}
-	return false;
-}
-
-static bool preload_add(struct thread_info *ti, unsigned long ea)
-{
-	unsigned long esid;
-	u8 idx;
-
-	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
-		/* EAs are stored >> 28 so 256MB segments don't need clearing */
-		if (ea & ESID_MASK_1T)
-			ea &= ESID_MASK_1T;
-	}
-
-	esid = ea >> SID_SHIFT;
-
-	if (preload_hit(ti, esid))
-		return false;
-
-	idx = (ti->slb_preload_tail + ti->slb_preload_nr) % SLB_PRELOAD_NR;
-	ti->slb_preload_esid[idx] = esid;
-	if (ti->slb_preload_nr == SLB_PRELOAD_NR)
-		ti->slb_preload_tail = (ti->slb_preload_tail + 1) % SLB_PRELOAD_NR;
-	else
-		ti->slb_preload_nr++;
-
-	return true;
-}
-
-static void preload_age(struct thread_info *ti)
-{
-	if (!ti->slb_preload_nr)
-		return;
-	ti->slb_preload_nr--;
-	ti->slb_preload_tail = (ti->slb_preload_tail + 1) % SLB_PRELOAD_NR;
-}
-
-void slb_setup_new_exec(void)
+/* Helper function to compare esids.  There are four cases to handle.
+ * 1. The system is not 1T segment size capable.  Use the GET_ESID compare.
+ * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare.
+ * 3. The system is 1T capable, only one of the two addresses is > 1T.  This is not a match.
+ * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare.
+ */
+static inline int esids_match(unsigned long addr1, unsigned long addr2)
 {
-	struct thread_info *ti = current_thread_info();
-	struct mm_struct *mm = current->mm;
-	unsigned long exec = 0x10000000;
+	int esid_1t_count;
 
-	/*
-	 * We have no good place to clear the slb preload cache on exec,
-	 * flush_thread is about the earliest arch hook but that happens
-	 * after we switch to the mm and have aleady preloaded the SLBEs.
-	 *
-	 * For the most part that's probably okay to use entries from the
-	 * previous exec, they will age out if unused. It may turn out to
-	 * be an advantage to clear the cache before switching to it,
-	 * however.
-	 */
-
-	/*
-	 * preload some userspace segments into the SLB.
-	 * Almost all 32 and 64bit PowerPC executables are linked at
-	 * 0x10000000 so it makes sense to preload this segment.
-	 */
-	if (!is_kernel_addr(exec)) {
-		if (preload_add(ti, exec))
-			slb_allocate_user(mm, exec);
-	}
-
-	/* Libraries and mmaps. */
-	if (!is_kernel_addr(mm->mmap_base)) {
-		if (preload_add(ti, mm->mmap_base))
-			slb_allocate_user(mm, mm->mmap_base);
-	}
-}
+	/* System is not 1T segment size capable. */
+	if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
+		return (GET_ESID(addr1) == GET_ESID(addr2));
 
-void preload_new_slb_context(unsigned long start, unsigned long sp)
-{
-	struct thread_info *ti = current_thread_info();
-	struct mm_struct *mm = current->mm;
-	unsigned long heap = mm->start_brk;
+	esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
+				((addr2 >> SID_SHIFT_1T) != 0));
 
-	/* Userspace entry address. */
-	if (!is_kernel_addr(start)) {
-		if (preload_add(ti, start))
-			slb_allocate_user(mm, start);
-	}
+	/* both addresses are < 1T */
+	if (esid_1t_count == 0)
+		return (GET_ESID(addr1) == GET_ESID(addr2));
 
-	/* Top of stack, grows down. */
-	if (!is_kernel_addr(sp)) {
-		if (preload_add(ti, sp))
-			slb_allocate_user(mm, sp);
-	}
+	/* One address < 1T, the other > 1T.  Not a match */
+	if (esid_1t_count == 1)
+		return 0;
 
-	/* Bottom of heap, grows up. */
-	if (heap && !is_kernel_addr(heap)) {
-		if (preload_add(ti, heap))
-			slb_allocate_user(mm, heap);
-	}
+	/* Both addresses are > 1T. */
+	return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
 }
 
-
 /* Flush all user entries from the segment table of the current processor. */
 void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 {
-	struct thread_info *ti = task_thread_info(tsk);
-	u8 i;
+	unsigned long pc = KSTK_EIP(tsk);
+	unsigned long stack = KSTK_ESP(tsk);
+	unsigned long exec_base;
 
 	/*
 	 * We need interrupts hard-disabled here, not just soft-disabled,
@@ -392,6 +304,7 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 		if (!mmu_has_feature(MMU_FTR_NO_SLBIE_B) &&
 		    offset <= SLB_CACHE_ENTRIES) {
 			unsigned long slbie_data = 0;
+			int i;
 
 			asm volatile("isync" : : : "memory");
 			for (i = 0; i < offset; i++) {
@@ -422,60 +335,67 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
 				     "isync"
 				     :: "r"(ksp_vsid_data),
 					"r"(ksp_esid_data));
-
-			get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
 		}
 
 		get_paca()->slb_cache_ptr = 0;
 	}
-	get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
+
+	copy_mm_to_paca(mm);
 
 	/*
-	 * We gradually age out SLBs after a number of context switches to
-	 * reduce reload overhead of unused entries (like we do with FP/VEC
-	 * reload). Each time we wrap 256 switches, take an entry out of the
-	 * SLB preload cache.
+	 * preload some userspace segments into the SLB.
+	 * Almost all 32 and 64bit PowerPC executables are linked at
+	 * 0x10000000 so it makes sense to preload this segment.
 	 */
-	tsk->thread.load_slb++;
-	if (!tsk->thread.load_slb) {
-		unsigned long pc = KSTK_EIP(tsk);
+	exec_base = 0x10000000;
 
-		preload_age(ti);
-		preload_add(ti, pc);
-	}
+	if (is_kernel_addr(pc) || is_kernel_addr(stack) ||
+	    is_kernel_addr(exec_base))
+		return;
 
-	for (i = 0; i < ti->slb_preload_nr; i++) {
-		unsigned long ea;
-		u8 idx;
+	slb_allocate(pc);
 
-		idx = (ti->slb_preload_tail + i) % SLB_PRELOAD_NR;
-		ea = (unsigned long)ti->slb_preload_esid[idx] << SID_SHIFT;
+	if (!esids_match(pc, stack))
+		slb_allocate(stack);
 
-		slb_allocate_user(mm, ea);
-	}
+	if (!esids_match(pc, exec_base) &&
+	    !esids_match(stack, exec_base))
+		slb_allocate(exec_base);
 }
 
-void slb_set_size(u16 size)
+static inline void patch_slb_encoding(unsigned int *insn_addr,
+				      unsigned int immed)
 {
-	mmu_slb_size = size;
+
+	/*
+	 * This function patches either an li or a cmpldi instruction with
+	 * a new immediate value. This relies on the fact that both li
+	 * (which is actually addi) and cmpldi both take a 16-bit immediate
+	 * value, and it is situated in the same location in the instruction,
+	 * ie. bits 16-31 (Big endian bit order) or the lower 16 bits.
+	 * The signedness of the immediate operand differs between the two
+	 * instructions however this code is only ever patching a small value,
+	 * much less than 1 << 15, so we can get away with it.
+	 * To patch the value we read the existing instruction, clear the
+	 * immediate value, and or in our new value, then write the instruction
+	 * back.
+	 */
+	unsigned int insn = (*insn_addr & 0xffff0000) | immed;
+	patch_instruction(insn_addr, insn);
 }
 
-static void cpu_flush_slb(void *parm)
-{
-	struct mm_struct *mm = parm;
-	unsigned long flags;
+extern u32 slb_miss_kernel_load_linear[];
+extern u32 slb_miss_kernel_load_io[];
+extern u32 slb_compare_rr_to_size[];
+extern u32 slb_miss_kernel_load_vmemmap[];
 
-	if (mm != current->active_mm)
+void slb_set_size(u16 size)
+{
+	if (mmu_slb_size == size)
 		return;
 
-	local_irq_save(flags);
-	slb_flush_and_rebolt();
-	local_irq_restore(flags);
-}
-
-void core_flush_all_slbs(struct mm_struct *mm)
-{
-	on_each_cpu(cpu_flush_slb, mm, 1);
+	mmu_slb_size = size;
+	patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size);
 }
 
 void slb_initialize(void)
@@ -497,16 +417,24 @@ void slb_initialize(void)
 #endif
 	if (!slb_encoding_inited) {
 		slb_encoding_inited = 1;
+		patch_slb_encoding(slb_miss_kernel_load_linear,
+				   SLB_VSID_KERNEL | linear_llp);
+		patch_slb_encoding(slb_miss_kernel_load_io,
+				   SLB_VSID_KERNEL | io_llp);
+		patch_slb_encoding(slb_compare_rr_to_size,
+				   mmu_slb_size);
+
 		pr_devel("SLB: linear  LLP = %04lx\n", linear_llp);
 		pr_devel("SLB: io      LLP = %04lx\n", io_llp);
+
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
+		patch_slb_encoding(slb_miss_kernel_load_vmemmap,
+				   SLB_VSID_KERNEL | vmemmap_llp);
 		pr_devel("SLB: vmemmap LLP = %04lx\n", vmemmap_llp);
 #endif
 	}
 
 	get_paca()->stab_rr = SLB_NUM_BOLTED - 1;
-	get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
-	get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
 
 	lflags = SLB_VSID_KERNEL | linear_llp;
 
@@ -530,13 +458,52 @@ void slb_initialize(void)
 	asm volatile("isync":::"memory");
 }
 
-static void slb_cache_update(unsigned long esid_data)
+static void insert_slb_entry(unsigned long vsid, unsigned long ea,
+			     int bpsize, int ssize)
 {
+	unsigned long flags, vsid_data, esid_data;
+	enum slb_index index;
 	int slb_cache_index;
 
 	if (cpu_has_feature(CPU_FTR_ARCH_300))
 		return; /* ISAv3.0B and later does not use slb_cache */
 
+	/*
+	 * We are irq disabled, hence should be safe to access PACA.
+	 */
+	VM_WARN_ON(!irqs_disabled());
+
+	/*
+	 * We can't take a PMU exception in the following code, so hard
+	 * disable interrupts.
+	 */
+	hard_irq_disable();
+
+	index = get_paca()->stab_rr;
+
+	/*
+	 * simple round-robin replacement of slb starting at SLB_NUM_BOLTED.
+	 */
+	if (index < (mmu_slb_size - 1))
+		index++;
+	else
+		index = SLB_NUM_BOLTED;
+
+	get_paca()->stab_rr = index;
+
+	flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
+	vsid_data = (vsid << slb_vsid_shift(ssize)) | flags |
+		    ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
+	esid_data = mk_esid_data(ea, ssize, index);
+
+	/*
+	 * No need for an isync before or after this slbmte. The exception
+	 * we enter with and the rfid we exit with are context synchronizing.
+	 * Also we only handle user segments here.
+	 */
+	asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data)
+		     : "memory");
+
 	/*
 	 * Now update slb cache entries
 	 */
@@ -558,196 +525,58 @@ static void slb_cache_update(unsigned long esid_data)
 	}
 }
 
-static enum slb_index alloc_slb_index(bool kernel)
+static void handle_multi_context_slb_miss(int context_id, unsigned long ea)
 {
-	enum slb_index index;
-
-	/*
-	 * The allocation bitmaps can become out of synch with the SLB
-	 * when the _switch code does slbie when bolting a new stack
-	 * segment and it must not be anywhere else in the SLB. This leaves
-	 * a kernel allocated entry that is unused in the SLB. With very
-	 * large systems or small segment sizes, the bitmaps could slowly
-	 * fill with these entries. They will eventually be cleared out
-	 * by the round robin allocator in that case, so it's probably not
-	 * worth accounting for.
-	 */
+	struct mm_struct *mm = current->mm;
+	unsigned long vsid;
+	int bpsize;
 
 	/*
-	 * SLBs beyond 32 entries are allocated with stab_rr only
-	 * POWER7/8/9 have 32 SLB entries, this could be expanded if a
-	 * future CPU has more.
+	 * We are always above 1TB, hence use high user segment size.
 	 */
-	if (get_paca()->slb_used_bitmap != U32_MAX) {
-		index = ffz(get_paca()->slb_used_bitmap);
-		get_paca()->slb_used_bitmap |= 1U << index;
-		if (kernel)
-			get_paca()->slb_kern_bitmap |= 1U << index;
-	} else {
-		/* round-robin replacement of slb starting at SLB_NUM_BOLTED. */
-		index = get_paca()->stab_rr;
-		if (index < (mmu_slb_size - 1))
-			index++;
-		else
-			index = SLB_NUM_BOLTED;
-		get_paca()->stab_rr = index;
-		if (index < 32) {
-			if (kernel)
-				get_paca()->slb_kern_bitmap |= 1U << index;
-			else
-				get_paca()->slb_kern_bitmap &= ~(1U << index);
-		}
-	}
-	BUG_ON(index < SLB_NUM_BOLTED);
-
-	return index;
+	vsid = get_vsid(context_id, ea, mmu_highuser_ssize);
+	bpsize = get_slice_psize(mm, ea);
+	insert_slb_entry(vsid, ea, bpsize, mmu_highuser_ssize);
 }
 
-static long slb_insert_entry(unsigned long ea, unsigned long context,
-				unsigned long flags, int ssize, bool kernel)
+void slb_miss_large_addr(struct pt_regs *regs)
 {
-	unsigned long vsid;
-	unsigned long vsid_data, esid_data;
-	enum slb_index index;
-
-	vsid = get_vsid(context, ea, ssize);
-	if (!vsid)
-		return -EFAULT;
+	enum ctx_state prev_state = exception_enter();
+	unsigned long ea = regs->dar;
+	int context;
 
-	index = alloc_slb_index(kernel);
-
-	vsid_data = __mk_vsid_data(vsid, ssize, flags);
-	esid_data = mk_esid_data(ea, ssize, index);
+	if (REGION_ID(ea) != USER_REGION_ID)
+		goto slb_bad_addr;
 
 	/*
-	 * No need for an isync before or after this slbmte. The exception
-	 * we enter with and the rfid we exit with are context synchronizing.
-	 * Also we only handle user segments here.
+	 * Are we beyound what the page table layout supports ?
 	 */
-	asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data));
+	if ((ea & ~REGION_MASK) >= H_PGTABLE_RANGE)
+		goto slb_bad_addr;
 
-	if (!kernel)
-		slb_cache_update(esid_data);
-
-	return 0;
-}
-
-static long slb_allocate_kernel(unsigned long ea, unsigned long id)
-{
-	unsigned long context;
-	unsigned long flags;
-	int ssize;
-
-	if ((ea & ~REGION_MASK) >= (1ULL << MAX_EA_BITS_PER_CONTEXT))
-		return -EFAULT;
-
-	if (id == KERNEL_REGION_ID) {
-		flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp;
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
-	} else if (id == VMEMMAP_REGION_ID) {
-		flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmemmap_psize].sllp;
-#endif
-	} else if (id == VMALLOC_REGION_ID) {
-		if (ea < H_VMALLOC_END)
-			flags = get_paca()->vmalloc_sllp;
-		else
-			flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_io_psize].sllp;
-	} else {
-		return -EFAULT;
-	}
-
-	ssize = MMU_SEGSIZE_1T;
-	if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
-		ssize = MMU_SEGSIZE_256M;
-
-	context = id - KERNEL_REGION_CONTEXT_OFFSET;
-
-	return slb_insert_entry(ea, context, flags, ssize, true);
-}
-
-static long slb_allocate_user(struct mm_struct *mm, unsigned long ea)
-{
-	unsigned long context;
-	unsigned long flags;
-	int bpsize;
-	int ssize;
+	/* Lower address should have been handled by asm code */
+	if (ea < (1UL << MAX_EA_BITS_PER_CONTEXT))
+		goto slb_bad_addr;
 
 	/*
 	 * consider this as bad access if we take a SLB miss
 	 * on an address above addr limit.
 	 */
-	if (ea >= mm->context.slb_addr_limit)
-		return -EFAULT;
+	if (ea >= current->mm->context.slb_addr_limit)
+		goto slb_bad_addr;
 
-	context = get_ea_context(&mm->context, ea);
+	context = get_ea_context(&current->mm->context, ea);
 	if (!context)
-		return -EFAULT;
-
-	if (unlikely(ea >= H_PGTABLE_RANGE)) {
-		WARN_ON(1);
-		return -EFAULT;
-	}
-
-	ssize = user_segment_size(ea);
-
-	bpsize = get_slice_psize(mm, ea);
-	flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
-
-	return slb_insert_entry(ea, context, flags, ssize, false);
-}
-
-long do_slb_fault(struct pt_regs *regs, unsigned long ea)
-{
-	unsigned long id = REGION_ID(ea);
-
-	/* IRQs are not reconciled here, so can't check irqs_disabled */
-	VM_WARN_ON(mfmsr() & MSR_EE);
-
-	if (unlikely(!(regs->msr & MSR_RI)))
-		return -EINVAL;
-
-	/*
-	 * SLB kernel faults must be very careful not to touch anything
-	 * that is not bolted. E.g., PACA and global variables are okay,
-	 * mm->context stuff is not.
-	 *
-	 * SLB user faults can access all of kernel memory, but must be
-	 * careful not to touch things like IRQ state because it is not
-	 * "reconciled" here. The difficulty is that we must use
-	 * fast_exception_return to return from kernel SLB faults without
-	 * looking at possible non-bolted memory. We could test user vs
-	 * kernel faults in the interrupt handler asm and do a full fault,
-	 * reconcile, ret_from_except for user faults which would make them
-	 * first class kernel code. But for performance it's probably nicer
-	 * if they go via fast_exception_return too.
-	 */
-	if (id >= KERNEL_REGION_ID) {
-		return slb_allocate_kernel(ea, id);
-	} else {
-		struct mm_struct *mm = current->mm;
-		long err;
-
-		if (unlikely(!mm))
-			return -EFAULT;
+		goto slb_bad_addr;
 
-		err = slb_allocate_user(mm, ea);
-		if (!err)
-			preload_add(current_thread_info(), ea);
-
-		return err;
-	}
-}
+	handle_multi_context_slb_miss(context, ea);
+	exception_exit(prev_state);
+	return;
 
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err)
-{
-	if (err == -EFAULT) {
-		if (user_mode(regs))
-			_exception(SIGSEGV, regs, SEGV_BNDERR, ea);
-		else
-			bad_page_fault(regs, ea, SIGSEGV);
-	} else if (err == -EINVAL) {
-		unrecoverable_exception(regs);
-	} else {
-		BUG();
-	}
+slb_bad_addr:
+	if (user_mode(regs))
+		_exception(SIGSEGV, regs, SEGV_BNDERR, ea);
+	else
+		bad_page_fault(regs, ea, SIGSEGV);
+	exception_exit(prev_state);
 }

arch/powerpc/mm/slb_low.S

+/*
+ * Low-level SLB routines
+ *
+ * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
+ *
+ * Based on earlier C version:
+ * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
+ *    Copyright (c) 2001 Dave Engebretsen
+ * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/firmware.h>
+#include <asm/feature-fixups.h>
+
+/*
+ * This macro generates asm code to compute the VSID scramble
+ * function.  Used in slb_allocate() and do_stab_bolted.  The function
+ * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
+ *
+ *	rt = register containing the proto-VSID and into which the
+ *		VSID will be stored
+ *	rx = scratch register (clobbered)
+ *	rf = flags
+ *
+ *	- rt and rx must be different registers
+ *	- The answer will end up in the low VSID_BITS bits of rt.  The higher
+ *	  bits may contain other garbage, so you may need to mask the
+ *	  result.
+ */
+#define ASM_VSID_SCRAMBLE(rt, rx, rf, size)				\
+	lis	rx,VSID_MULTIPLIER_##size@h;				\
+	ori	rx,rx,VSID_MULTIPLIER_##size@l;				\
+	mulld	rt,rt,rx;		/* rt = rt * MULTIPLIER */	\
+/*									\
+ * powermac get slb fault before feature fixup, so make 65 bit part     \
+ * the default part of feature fixup					\
+ */									\
+BEGIN_MMU_FTR_SECTION							\
+	srdi	rx,rt,VSID_BITS_65_##size;				\
+	clrldi	rt,rt,(64-VSID_BITS_65_##size);				\
+	add	rt,rt,rx;						\
+	addi	rx,rt,1;						\
+	srdi	rx,rx,VSID_BITS_65_##size;				\
+	add	rt,rt,rx;						\
+	rldimi	rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_65_##size)); \
+MMU_FTR_SECTION_ELSE							\
+	srdi	rx,rt,VSID_BITS_##size;					\
+	clrldi	rt,rt,(64-VSID_BITS_##size);				\
+	add	rt,rt,rx;		/* add high and low bits */	\
+	addi	rx,rt,1;						\
+	srdi	rx,rx,VSID_BITS_##size;	/* extract 2^VSID_BITS bit */	\
+	add	rt,rt,rx;						\
+	rldimi	rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_##size)); \
+ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_68_BIT_VA)
+
+
+/* void slb_allocate(unsigned long ea);
+ *
+ * Create an SLB entry for the given EA (user or kernel).
+ * 	r3 = faulting address, r13 = PACA
+ *	r9, r10, r11 are clobbered by this function
+ *	r3 is preserved.
+ * No other registers are examined or changed.
+ */
+_GLOBAL(slb_allocate)
+	/*
+	 * Check if the address falls within the range of the first context, or
+	 * if we may need to handle multi context. For the first context we
+	 * allocate the slb entry via the fast path below. For large address we
+	 * branch out to C-code and see if additional contexts have been
+	 * allocated.
+	 * The test here is:
+	 *   (ea & ~REGION_MASK) >= (1ull << MAX_EA_BITS_PER_CONTEXT)
+	 */
+	rldicr. r9,r3,4,(63 - MAX_EA_BITS_PER_CONTEXT - 4)
+	bne-	8f
+
+	srdi	r9,r3,60		/* get region */
+	srdi	r10,r3,SID_SHIFT	/* get esid */
+	cmpldi	cr7,r9,0xc		/* cmp PAGE_OFFSET for later use */
+
+	/* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */
+	blt	cr7,0f			/* user or kernel? */
+
+	/* Check if hitting the linear mapping or some other kernel space
+	*/
+	bne	cr7,1f
+
+	/* Linear mapping encoding bits, the "li" instruction below will
+	 * be patched by the kernel at boot
+	 */
+.globl slb_miss_kernel_load_linear
+slb_miss_kernel_load_linear:
+	li	r11,0
+	/*
+	 * context = (ea >> 60) - (0xc - 1)
+	 * r9 = region id.
+	 */
+	subi	r9,r9,KERNEL_REGION_CONTEXT_OFFSET
+
+BEGIN_FTR_SECTION
+	b	.Lslb_finish_load
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
+	b	.Lslb_finish_load_1T
+
+1:
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+	cmpldi	cr0,r9,0xf
+	bne	1f
+/* Check virtual memmap region. To be patched at kernel boot */
+.globl slb_miss_kernel_load_vmemmap
+slb_miss_kernel_load_vmemmap:
+	li	r11,0
+	b	6f
+1:
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+	/*
+	 * r10 contains the ESID, which is the original faulting EA shifted
+	 * right by 28 bits. We need to compare that with (H_VMALLOC_END >> 28)
+	 * which is 0xd00038000. That can't be used as an immediate, even if we
+	 * ignored the 0xd, so we have to load it into a register, and we only
+	 * have one register free. So we must load all of (H_VMALLOC_END >> 28)
+	 * into a register and compare ESID against that.
+	 */
+	lis	r11,(H_VMALLOC_END >> 32)@h	// r11 = 0xffffffffd0000000
+	ori	r11,r11,(H_VMALLOC_END >> 32)@l	// r11 = 0xffffffffd0003800
+	// Rotate left 4, then mask with 0xffffffff0
+	rldic	r11,r11,4,28			// r11 = 0xd00038000
+	cmpld	r10,r11				// if r10 >= r11
+	bge	5f				//   goto io_mapping
+
+	/*
+	 * vmalloc mapping gets the encoding from the PACA as the mapping
+	 * can be demoted from 64K -> 4K dynamically on some machines.
+	 */
+	lhz	r11,PACAVMALLOCSLLP(r13)
+	b	6f
+5:
+	/* IO mapping */
+.globl slb_miss_kernel_load_io
+slb_miss_kernel_load_io:
+	li	r11,0
+6:
+	/*
+	 * context = (ea >> 60) - (0xc - 1)
+	 * r9 = region id.
+	 */
+	subi	r9,r9,KERNEL_REGION_CONTEXT_OFFSET
+
+BEGIN_FTR_SECTION
+	b	.Lslb_finish_load
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
+	b	.Lslb_finish_load_1T
+
+0:	/*
+	 * For userspace addresses, make sure this is region 0.
+	 */
+	cmpdi	r9, 0
+	bne-	8f
+        /*
+         * user space make sure we are within the allowed limit
+	 */
+	ld	r11,PACA_SLB_ADDR_LIMIT(r13)
+	cmpld	r3,r11
+	bge-	8f
+
+	/* when using slices, we extract the psize off the slice bitmaps
+	 * and then we need to get the sllp encoding off the mmu_psize_defs
+	 * array.
+	 *
+	 * XXX This is a bit inefficient especially for the normal case,
+	 * so we should try to implement a fast path for the standard page
+	 * size using the old sllp value so we avoid the array. We cannot
+	 * really do dynamic patching unfortunately as processes might flip
+	 * between 4k and 64k standard page size
+	 */
+#ifdef CONFIG_PPC_MM_SLICES
+	/* r10 have esid */
+	cmpldi	r10,16
+	/* below SLICE_LOW_TOP */
+	blt	5f
+	/*
+	 * Handle hpsizes,
+	 * r9 is get_paca()->context.high_slices_psize[index], r11 is mask_index
+	 */
+	srdi    r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT + 1) /* index */
+	addi	r9,r11,PACAHIGHSLICEPSIZE
+	lbzx	r9,r13,r9		/* r9 is hpsizes[r11] */
+	/* r11 = (r10 >> (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)) & 0x1 */
+	rldicl	r11,r10,(64 - (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)),63
+	b	6f
+
+5:
+	/*
+	 * Handle lpsizes
+	 * r9 is get_paca()->context.low_slices_psize[index], r11 is mask_index
+	 */
+	srdi    r11,r10,1 /* index */
+	addi	r9,r11,PACALOWSLICESPSIZE
+	lbzx	r9,r13,r9		/* r9 is lpsizes[r11] */
+	rldicl	r11,r10,0,63		/* r11 = r10 & 0x1 */
+6:
+	sldi	r11,r11,2  /* index * 4 */
+	/* Extract the psize and multiply to get an array offset */
+	srd	r9,r9,r11
+	andi.	r9,r9,0xf
+	mulli	r9,r9,MMUPSIZEDEFSIZE
+
+	/* Now get to the array and obtain the sllp
+	 */
+	ld	r11,PACATOC(r13)
+	ld	r11,mmu_psize_defs@got(r11)
+	add	r11,r11,r9
+	ld	r11,MMUPSIZESLLP(r11)
+	ori	r11,r11,SLB_VSID_USER
+#else
+	/* paca context sllp already contains the SLB_VSID_USER bits */
+	lhz	r11,PACACONTEXTSLLP(r13)
+#endif /* CONFIG_PPC_MM_SLICES */
+
+	ld	r9,PACACONTEXTID(r13)
+BEGIN_FTR_SECTION
+	cmpldi	r10,0x1000
+	bge	.Lslb_finish_load_1T
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
+	b	.Lslb_finish_load
+
+8:	/* invalid EA - return an error indication */
+	crset	4*cr0+eq		/* indicate failure */
+	blr
+
+/*
+ * Finish loading of an SLB entry and return
+ *
+ * r3 = EA, r9 = context, r10 = ESID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
+ */
+.Lslb_finish_load:
+	rldimi  r10,r9,ESID_BITS,0
+	ASM_VSID_SCRAMBLE(r10,r9,r11,256M)
+	/* r3 = EA, r11 = VSID data */
+	/*
+	 * Find a slot, round robin. Previously we tried to find a
+	 * free slot first but that took too long. Unfortunately we
+	 * dont have any LRU information to help us choose a slot.
+	 */
+
+	mr	r9,r3
+
+	/* slb_finish_load_1T continues here. r9=EA with non-ESID bits clear */
+7:	ld	r10,PACASTABRR(r13)
+	addi	r10,r10,1
+	/* This gets soft patched on boot. */
+.globl slb_compare_rr_to_size
+slb_compare_rr_to_size:
+	cmpldi	r10,0
+
+	blt+	4f
+	li	r10,SLB_NUM_BOLTED
+
+4:
+	std	r10,PACASTABRR(r13)
+
+3:
+	rldimi	r9,r10,0,36		/* r9  = EA[0:35] | entry */
+	oris	r10,r9,SLB_ESID_V@h	/* r10 = r9 | SLB_ESID_V */
+
+	/* r9 = ESID data, r11 = VSID data */
+
+	/*
+	 * No need for an isync before or after this slbmte. The exception
+	 * we enter with and the rfid we exit with are context synchronizing.
+	 */
+	slbmte	r11,r10
+
+	/* we're done for kernel addresses */
+	crclr	4*cr0+eq		/* set result to "success" */
+	bgelr	cr7
+
+	/* Update the slb cache */
+	lhz	r9,PACASLBCACHEPTR(r13)	/* offset = paca->slb_cache_ptr */
+	cmpldi	r9,SLB_CACHE_ENTRIES
+	bge	1f
+
+	/* still room in the slb cache */
+	sldi	r11,r9,2		/* r11 = offset * sizeof(u32) */
+	srdi    r10,r10,28		/* get the 36 bits of the ESID */
+	add	r11,r11,r13		/* r11 = (u32 *)paca + offset */
+	stw	r10,PACASLBCACHE(r11)	/* paca->slb_cache[offset] = esid */
+	addi	r9,r9,1			/* offset++ */
+	b	2f
+1:					/* offset >= SLB_CACHE_ENTRIES */
+	li	r9,SLB_CACHE_ENTRIES+1
+2:
+	sth	r9,PACASLBCACHEPTR(r13)	/* paca->slb_cache_ptr = offset */
+	crclr	4*cr0+eq		/* set result to "success" */
+	blr
+
+/*
+ * Finish loading of a 1T SLB entry (for the kernel linear mapping) and return.
+ *
+ * r3 = EA, r9 = context, r10 = ESID(256MB), r11 = flags, clobbers r9
+ */
+.Lslb_finish_load_1T:
+	srdi	r10,r10,(SID_SHIFT_1T - SID_SHIFT)	/* get 1T ESID */
+	rldimi  r10,r9,ESID_BITS_1T,0
+	ASM_VSID_SCRAMBLE(r10,r9,r11,1T)
+
+	li	r10,MMU_SEGSIZE_1T
+	rldimi	r11,r10,SLB_VSID_SSIZE_SHIFT,0	/* insert segment size */
+
+	/* r3 = EA, r11 = VSID data */
+	clrrdi	r9,r3,SID_SHIFT_1T	/* clear out non-ESID bits */
+	b	7b
+
+
+_ASM_NOKPROBE_SYMBOL(slb_allocate)
+_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_linear)
+_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_io)
+_ASM_NOKPROBE_SYMBOL(slb_compare_rr_to_size)
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+_ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_vmemmap)
+#endif

arch/powerpc/mm/slice.c

@@ -207,6 +207,23 @@ static bool slice_check_range_fits(struct mm_struct *mm,
 	return true;
 }
 
+static void slice_flush_segments(void *parm)
+{
+#ifdef CONFIG_PPC64
+	struct mm_struct *mm = parm;
+	unsigned long flags;
+
+	if (mm != current->active_mm)
+		return;
+
+	copy_mm_to_paca(current->active_mm);
+
+	local_irq_save(flags);
+	slb_flush_and_rebolt();
+	local_irq_restore(flags);
+#endif
+}
+
 static void slice_convert(struct mm_struct *mm,
 				const struct slice_mask *mask, int psize)
 {
@@ -272,9 +289,6 @@ static void slice_convert(struct mm_struct *mm,
 	spin_unlock_irqrestore(&slice_convert_lock, flags);
 
 	copro_flush_all_slbs(mm);
-#ifdef CONFIG_PPC64
-	core_flush_all_slbs(mm);
-#endif
 }
 
 /*
@@ -488,9 +502,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 		 * be already initialised beyond the old address limit.
 		 */
 		mm->context.slb_addr_limit = high_limit;
-#ifdef CONFIG_PPC64
-		core_flush_all_slbs(mm);
-#endif
+
+		on_each_cpu(slice_flush_segments, mm, 1);
 	}
 
 	/* Sanity checks */
@@ -652,10 +665,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 		(SLICE_NUM_HIGH &&
 		 !bitmap_empty(potential_mask.high_slices, SLICE_NUM_HIGH))) {
 		slice_convert(mm, &potential_mask, psize);
-#ifdef CONFIG_PPC64
 		if (psize > MMU_PAGE_BASE)
-			core_flush_all_slbs(mm);
-#endif
+			on_each_cpu(slice_flush_segments, mm, 1);
 	}
 	return newaddr;
 
@@ -746,20 +757,6 @@ void slice_init_new_context_exec(struct mm_struct *mm)
 		bitmap_fill(mask->high_slices, SLICE_NUM_HIGH);
 }
 
-#ifdef CONFIG_PPC_BOOK3S_64
-void slice_setup_new_exec(void)
-{
-	struct mm_struct *mm = current->mm;
-
-	slice_dbg("slice_setup_new_exec(mm=%p)\n", mm);
-
-	if (!is_32bit_task())
-		return;
-
-	mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
-}
-#endif
-
 void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 			   unsigned long len, unsigned int psize)
 {

arch/powerpc/xmon/xmon.c

@@ -2394,9 +2394,7 @@ static void dump_one_paca(int cpu)
 			}
 		}
 		DUMP(p, vmalloc_sllp, "%#-*x");
-		DUMP(p, stab_rr, "%#-*x");
-		DUMP(p, slb_used_bitmap, "%#-*x");
-		DUMP(p, slb_kern_bitmap, "%#-*x");
+		DUMP(p, stab_rr, "%#-*llx");
 
 		if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) {
 			DUMP(p, slb_cache_ptr, "%#-*x");